mackenzie



R. I. MACKENZIE. EXHAUST MUFFLER.

APPLICATION HLED MAR- 16' 1911.

Patented Oct. 14, 1919;

UNITED sTATEs PATENT. OFEICE.

ROY J'. MACKENZIE, OF BUFFALO, NEW YORK, ASSIGNGR TO BUFFALO PRESSED STEEL (10., OF NEW YORK, N. Y.

EXHAUST-MUFFLER.

New York, have invented a new and useful Improvement in Exhaust-Mufflers, of which the following is a specification.

This invention relates to improvements in mufliers or silencers of the kind commonly usedin connection with internal combustion engines to reduce or eliminate the noise caused by the engine exhaust.

The objects of the invention are to pro- .duce a muiller or silencer of this kind of ef-l ficient and inexpensive construction which has'a pluralityef shells or tubes arran ed to form expansion chambers havingiametrically oppositely disposed portions into which the exhaust gases pass; also to provide means of improved construction for guiding the exhaust gases from one chamber to another; also to improve devicesof this kind in other respects hereinafter specified.

In the accompanying drawings:

Figure 1 is a central longitudinal sectional elevation of a mufller embodying the invention.

Figs. 2 and 3 are transverse sectional elevations thereof on lines 2'2 and 3-3, respectively, Fig. 1.

Fig. 4 is a fragmentary longitudinal sectional elevation thereof on line 4-4, Fig. 3.

The mufiier shown in the drawings in' cludes an inner cylindrical tube or shell A of substantially circular crosssection, into which the'exhaust gases pass from the engine, an intermediate tube or shell B of elliptical or analogous cross-section having its smallest diameter greater than the diaameter of the shell A and arranged concentrio with regard to the nner tube, and an outer tube or shell C, also of substantially circular cross-section and of greater diameter than the largest ,diameter of the elliptic shell B and arranged concentric with regard to the inner tube A. The tubes .or

- shells are held in place with regard to each other by means of a head D at the inlet end of the muflier, and a head E at the discharge end thereof. The heads are preferably made of sheet metal and have shoulders or steps (Z (Z and e c by means of which the shells are held in place. The heads are preferably secured to and held in place by the outer shell C.

Specification of Letters Patent.

Application filed March 16. 1917. Serial No. 155,332.

The shells A and B are so arranged with regard to each other as to form an inner expansion chamber having two expansion parts or halves F and G at diametrically opposite sides of the shell A. These half chambers join at opposite sides of the inner shell A, at the points of smallest diameter of the elliptic shell, and increase in sectional area from these points to the points of greatest diameter of the elliptic shell. The cross section of each of these half chambers is therefore substantially crescent-shaped. The inner shell is provided with discharge openingsH H at the junctions of the two halves of the inner chamber, so that the gases from the inner shell enter the inner chamber at the portions thereof of smallest cross-sectional area and are'divided and flow from opposite sides of the half chambers F and G toth portions thereof of largest crosssectional area, at which portions the divided parts of the gases impinge and are again united. 1

A similar outer chamberscomprising two half chambers I K is formed by the elliptic shell 3 and the outer shell (3, these half chambers having their smallest cross-sectional areas at the greatest diameter of the elliptic shell, and their greatest cross-sectional areas at the smallest diameter of the elliptic shell. The elliptic shell has dis charge openings L L for the gases adjacent to the points of greatest diameter of the elliptic shell so that the gases enter the outer chamber at the smallest portions thereof and are-sub-divided so as to pass toward the portions of the half chambers I K havingthe greatest cross-sectional area, at which portions the sub-divided parts of the gases impinge and are again united. The gases are discharged from the parts I K of the outer chamber through discharge openings M, in the head E of the muffler.

' The discharge openings in the shells and in the mnillerhead E are preferably so arranged as to cause the gases to flow lengthwise of the chambers from one end of the muffler to the other end before being discharged. For this purpose, in the construction illustrated, the discharge openings H H and L L arearranged respectively adjacent to the discharge and inlet ends of the mufller. The gases are therefore not only divided and passed circumfcrentially in opposite directions in the two parts of each Patented Oct. 14,1919.

chamberof the muiiler to impinge and A and B respectively, and the metal adja cent to the'holes or openings is preferably so shaped as to produce deflectors h it and Z Z, which cause the gases to flow toward the larger portions of the chambers. The

deflectors shown in the, drawings are formed by'making cuts or slits in the shells and bending portions of the metal adjacent to the slits outwardly, as shown. The deflectors k h are shaped to direct the portion of the gases passing through the openings H II into the part F of/the in ner chamber and the deflectors h it direct the gases from the openings H H into the part G of the inner chamber. In the same manner the deflectors Z1 and Z Z direct the gases respectively into the arts I and K of the outer chamber.

T e gases after passing through the openings M in the headE .of the mufiier enter into a compartment N, formed in the discharge endof the -mutiler" by the head E and an outer head 0. The outer head is provided with a discharge nozzle or pipe 0 through which the exhaust gases pass out of the mufiier. The head D also is provided with a short tube or pipe 77 which may be connected with the exhaustpipe of an engine (notshown) and through which the exhaust gases enter the tube A. Other means may be employed, if desired, forad mitting the gases to the shell A'and for dis posing of the gases after they have passed out of the parts I K of the outer chamber.

' The parts F G and I K of the inner and outer chambers may if desired be separated from each other and form separate chamber's,'and itf'is' understood that the words parts of;a chamber as used in the specification and claims are intended to apply also to structures in which the parts are separated from each other.

The muffler described has the advantages of being inexpensive to manufacture and thoroughly efficient. By dividing the gases and causing the divided portions to impinge in diametrically oppositeparts of the em pansion chambers and against diametrically opposite portions of a shell, the impact or momentum of the, gases in one chamber is neutralized or counteracted by the momenturn .of the gases in'the diametricallyopposite chamber, thereby reducing the noiseof the exhaust. The fact that the gases flow lengthwise in the chambers as Well as circumferentially also tends to silence the exhaust and cause the gases to flow from the noise. l

Three shells are employed in the mufller discharge end of the muffler with very little in said oppositely arranged parts at pact takes place.

shown, but itwis understood that as many shells as may be desired can be used, alter nate shells being of elliptical cross-section.

I claim as my invention: 1. A mufllerhaving an inner cylindrical shell, an outer cylindrical shell, and an intion from the portions thereof at'which the gases enter to the portions thereof at which the gases are discharged.

2. A muflier having a plurallty of substan tially concentrically arranged shells of cir cular and elliptical cross-section, said circular and elliptic shells being alternately arranged, andmeans for permitting gases to flow from one shell to another, said shells forming chambers which vary in cross-section from the portions thereof at which the gases enter to the portions thereof at which the gases are d scharged.

3. A mufiler having two shells arrangedto form expansion chambers having diametrically opposite parts, and means for simultaneously discharging gas into said parts in opposite directions to cause the gas to impinge in said parts at diametrically opposite sides ofthe said shells, whereby the impact of gas in one part of a chamber will be neutralized by the impact of gas in the other part of the chamber.

4. A muflier having a plurality of shells forming an expansion chamber which has two diametrically oppositely arranged parts, means for admitting gases to said chamber at diametrically opposite sides thereof, the gases flowing in opposite directions in each part of said chamber from the points of admission and impacting simultaneously in said diametrically oppositely arranged parts at points intermediate of the points of admission, whereby the impact in one of said parts is neutralized by the impact in said other part.

5. A mufiler having-a plurality of shells arranged to form 'an expansion chamber for exhaust gas, said chamber having two oppositely arranged parts, meansfor admitting gas to said chamber at opposite sides of said chamber and causing currents of gas to flow in opposite directions in each partof said chamber from the points of admission,

the currents of gas impacting simultaneously oints intermediate of the points of admission, whereby the impact in one ofsaid parts is neutralized by the impact in said other part,

and means for discharging gas from said chamber at the portions thereof at which im- '6."'A mufiier having two shells arranged to form expansion chambers having diametsection and to impinge in said last men tioned portions of the chambers.

7. A muffler having two shells arranged to form expansion chambers having diametrically opposite parts of substantially crescent-shaped cross-section, means for simultaneously admitting gas into portions of said chambers of small cross-section to cause the gas to flow in opposite directions in said parts to the'portions'of larger cross section and to impinge in said last mentioned portions of the chambers, and gas discharge openings in said chambers in the parts thereof of-larger cross-section.

8. A muilier having a plurality'pf shells arranged to form a plurality of chambers having oppositely disposed partsof substan-' tially crescent-shaped cross-section, means for simultaneously admitting gas into the.

portions of smallest cross-section of the chambers, and means for discharging gas from said chambers at the portions thereof of larger cross-section into portions of small cross-section of an adjacent chamber.

9. A mufiier having a plurality of substantially concentrically arranged shells of circular and elliptical cross-section, said circular and elliptic shells being alternately arranged forming chan'iber's of varying crosssection, and meansior causing to flow from one chamber to another and to entersaid chambers at the smaller cross-section.

10. A mufiier having a plurality of sub stantially concentrically arranged shells of circular and elliptical cross-section, said Cll"? portions thereof of ranged, forming chambers of varying cross section, and means for causing gas to flow into said chambersin opposite directions from the portions thereof of smaller cross section to the portions of larger cross-sec-v tion and to impinge in said last mentioned portions.

11. A muflier having a plurality of substantially concentrically arranged shells of circular and elliptical cross-section, said cir cular and elliptic shells being alternately arranged to form chambers havingoppositely disposed parts of substantially crescent shaped cross-section. and means for adcular and elliptic shells being alternately ar- M cular and elliptic shells being alternately arranged to form chambers having oppositely disposed parts of substantially crescent-shaped cross-section, and means for si multaneously admitting gas to the portions of small cross-section of two oppositely disposed parts of a chamber to cause the gas to flow in. opposite directions in each of said parts and to impinge'in the portions thereof of greater cross-section, the impact of the gas in one part of a chambervbeing oounteracted b the impact of the gas in the other part 0 tliech'a'mber.v

13. A mufiier having an inner cylindrical shell into which the gases of the exhaust enter, a second shell arranged about said cylindrical shell and forming therewith two chambers, each having diametrically opposed p'arts, four discharge openings in said inner shell through which four portions of the gas pass, two portion-s passing in opposite directions in eachof the parts of a chamber, whereby the impact of the portions of the gas act inopposite directions on said second shell.

14. A muffler having an inner cylindrical shell into which the gases of the exhaust enter, and an elliptical shell arranged substantially concentric with and around said inner shell and forming therewith a chamber having two diametrically opposed parts of substantially crescent-shaped cross section, four discharge openings being provided .in said inner shell two openings being pro vided for each part of said chamber and admitting gas to the portions of the cham bers of small cross-section and causing portions of gas to pass 1n opposite directions in each part of said chamber toward the larger portions thereof.

15. A muifier having an inner cylindrical shell into which the gases of the exhaust enter, an elliptical shell arranged substantially concentric with and around said inner shell and forming therewith a chamber having two diametrically opposed parts of substantially crescent-shaped cross-section, four discharge openings being provided in said inner shell, two openings being provided for each part of said chamber and admitting gas to the portions of the chambers of small cross-section and causing portions of gas to pass in opposite directions in each part of said chamber toward the larger portions ing two diametrically opposed parts of substantially crescent shaped cross-section, four discharge openings being provided in said inner shell, two openings being provided for each part of said chamber and admitting gas to the portions of the chambers of small cross-section and causing portions of gas to pass in opposite directions in each part of said chamber toward the larger portions thereof, and an outer cylindrical shell arranged about said elliptical shell and forming therewith a chamber having two substantially crescent-shaped parts arranged substantially at right angles to the parts of said first mentioned chamber; said elliptical shell having openings to discharge gas from the portions of said first mentioned chamberof greater cross-section to parts of the second mentioned chamber of smaller cross-section.

17. A mufiler having an inner cylindrical shell into which the gases of the exhaust enter, an elliptical shell arranged substan tially concentric with and around said inner shell and forming therewith a chamber-having two diametrically opposed parts of sub stantially crescent-shaped cross-section, four discharge openings being provided in said inner shell, two openings being provided for each part of said chamber and admitting gas to the portions of the chambers of small cross-section and causing portions of gas to pass in opposite directions in each part of said chamber toward the larger portions thereof, and an outer cylindrical shell arranged about said elliptical shell and forming therewith a chamber having two substantially crescent-shaped parts arranged substantially at right angles to the parts of said first mentioned chamber, said elliptical shell having openings' to discharge gas from the portions of said first mentioned chamber of greater cross-section to parts of the second mentioned chamber of smaller cross-section, the openings in said inner shell and in said elliptical shell bein adjacent to the opposite ends of said mui er.

18. A mufller having an inner cylindrical shell, an outer cylindrical shell, and an intermediate elliptical shell, said shells being arranged substantially concentrically, said elliptical shell extending into proximity to said inner shell at the portions thereof of smallest diameter and extending into proximity to said outer shell at the portions thereof of greatest diameter, discharge openings for gas in said inner shell adjacent to the points of smallest diameterof the ellipse, and discharge openingsin said elliptical shell adjacent to the points of largest diameter thereof.

19. A mufiler having a plurality of shells arranged to form an expansion chamber for exhaust gas,.said chamber having two oppositely arranged parts, means for admitting gas to said chamber at opposite sides of said chamber, and deflectors for causing currents of gas to flow in opposite directions from the points of admission to said oppositely arranged parts of the chamber, and causing currents of gas to impact simultaneously in said oppositely arranged parts, whereby the impact in one of said parts is neutralized by the impact in said other part.

Witness my hand, the lstday of February, 1917.

' ROY J. MACKENZIE.

Witnesses:

M. J PITMAN, A. L. MCGEE. 

